[ZFS] starving reads while idle disks

[David P. Discher]

Do you see the same read-stravation when writing the tar to a file ? (possibly outside the zpool).

I have anecdotal suspicion that /dev/null has some performance hit of blocking or locking. 

-dpd


On Sep 17, 2011, at 5:02 AM, Lytochkin Boris wrote:

> While runnig `tar cf - . >/dev/null', `vmstat -i' shows ~200
> interrupts per second for mpt. If I enable scrub on that pool,
> interrupts bump upto 5k ips resulting 12Mb/s scrub speed and disks
> busy percentage raises upto 100%. No warnings are shown in logs in
> both cases.